xn--6oce0hoc.com was setup to show how unicode can be used like an old aol punter. To see this in action use https://www.punycoder.com can help convert the punycode into the crashing character and display it to a Mac device
This reminds me of AOL Punters from a long time ago. Back then they were a way of booting people off the internet. This bug shows how the old is new and things don't change.
As of 2018-02-13 https://openradar.appspot.com/37458268 was still open indicating that this will continue to work on MacOS and iOS.
This domain was purchased for testing, and not for malicious use, if the url that got you here crashed something, sorry, I hope Apple fixes the bug soon
For additional musings on unicode see